Rotary caulking device, method of manufacturing hub unit bearing and method of manufacturing vehicle

ABSTRACT

A hub main body (13z) is supported by a support portion (18). At least one block (22) is engaged with a stationary flange (6) of an outer ring (2). As a support plate (21) rotates, the outer ring (2) rotates. A caulking portion (16) is formed by pressing a pressing die (20) on a cylindrical portion (31).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/JP2018/039596 filed Oct. 25, 2018, claiming priority based onJapanese Patent Application No. 2017-223090 filed Nov. 20, 2017, thecontents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a method of manufacturing a hub unitbearing for rotatably supporting a wheel and a braking rotor of avehicle relative to a suspension device.

BACKGROUND ART

Wheels and braking rotors of a vehicle are rotatably supported by hubunit bearings relative to the suspension device. A hub unit bearing isconfigured by rotatably supporting a hub, which supports a wheel and abraking rotor, via a plurality of rolling elements on an inner diameterside of an outer ring supported by and fixed to a suspension device. Thehub is configured by supporting and fixing an inner ring to a hub mainbody. The hub main body has a rotary flange for supporting the wheel andthe braking rotor. The inner ring, which is a separate member, isexternally fitted into an outer circumferential surface on the hub mainbody. An axially inner end face of the inner ring is pressed and held bya caulking portion provided at an axially inner end portion of the hubmain body. The caulking portion is formed by plastically deforming acylindrical portion provided at the axially inner end portion of the hubmain body outward in the radial direction.

Patent Document 1 (Japanese Patent Application, Publication No.2003-21153) discloses a method of forming a caulking portion byplastically deforming a cylindrical portion outward in the radialdirection. In this method, while a tip portion of a pressing die (acaulking jig) having a central axis inclined relative to a central axisof a hub main body (a shaft portion) is pressed against a cylindricalportion (a cylinder-like portion), the pressing die is gyrated aroundthe central axis of the hub main body. In the method disclosed in PatentDocument 1, balls that are rolling elements are rotated and revolved byrotating an outer ring while processing the caulking portion. Thisprevents the formation of indentations on the inner and outer rings.

In the structure disclosed in Patent Document 1, a rotary drive unit (arotation assist jig) for rotating the outer ring is configured byattaching pins to a plurality of places on a circumference of an annularplate. When processing the caulking portion, while the pins are insertedinto support holes (bolt mounting holes) provided in a stationary flange(a flange) of the outer ring, or the pins are hooked on an outercircumferential surface of the stationary flange, the outer ring isdriven to rotate by rotating the rotary drive unit using a motor.

CITATION LIST Patent Literature

[Patent Document 1] Japanese Patent Application, Publication No.2003-21153

SUMMARY OF INVENTION Technical Problem

In the structure described in Patent Document 1, the pins of the rotarydrive unit are inserted into the support holes of the stationary flangeor are hooked on the outer circumferential surface of the stationaryflange. Therefore, when assembling the rotary drive unit (rotationassist jig) to the stationary flange, phase alignment in thecircumferential direction is required, whereby the productivity isreduced accordingly. In addition, in order to prevent the outer ringfrom rotating (co-rotating) with the rotary drive unit when implementingphase alignment work of the rotary drive unit and the stationary flangein the circumferential direction, it is necessary to press down theouter ring using a pressing rod. Such a pressing rod has to be retractedwhen processing the caulking portion, and it is necessary to provide anactuator for allowing the rod to move close to and away from the outerring, which increases the costs of the manufacturing device.

An object of the present invention is to realize a rotary caulkingdevice and a method of manufacturing a hub unit bearing in whichproductivity can be improved and costs can be reduced without need forperforming phase alignment of a rotary drive unit and a stationaryflange in the circumferential direction.

Solution to Problem

A rotary caulking device according to one aspect of the presentinvention includes a support portion, a rotary drive unit, and apressing die. The support portion has a reference axis. The rotary driveunit has an annular support plate which is supported to be able to moveclose to and away from the support portion and which can be driven torotate about a central axis coaxial with the reference axis, and blockswhich are supported at one or more places of a circumference of thesupport plate to be able to be displaced in an axial direction thereof.The pressing die is supported to be able to perform a swinging androtary motion about a main axis coaxial with the reference axis, and isrotatably supported about a rotation axis inclined relative to the mainaxis.

The blocks may be supported at a plurality of places of the supportplate in a circumferential direction thereof.

Elastic forces directed in a direction toward the support portion withrespect to the axial direction may be applied to the blocks. In thiscase, elastic members can be installed between the support plate and theblocks.

A rolling bearing or a sliding bearing may be provided at a tip portionof the blocks. In this case, the rolling bearing or the sliding bearingcan be made of, for example, a synthetic resin such as a polyamide resinor a polytetrafluoroethylene resin.

A rotary caulking device according to another aspect of the presentinvention is used for manufacturing a bearing unit. The rotary caulkingdevice includes a base which supports a unit main body of the bearingunit, a pressing die which is configured to perform a caulking motionrelative to the unit main body to which an inner ring is attached, andan adapter via which an outer ring moves around an axis of the unit mainbody. The adapter has an adapter main body, and at least one block heldin the adapter main body. The at least one block is disposed to bemovable in the axial direction of the unit main body relative to theadapter main body.

A method of manufacturing a hub unit bearing according to another aspectof the present invention includes supporting a hub main body, andcaulking the hub main body to which an inner ring is attached. Thecaulking includes pressing a pressing die on the hub main body while thepressing die rotates, and moving an outer ring around an axis of the hubmain body via an adapter. The adapter has an adapter main body and atleast one block held in the adapter main body. The at least one block isdisposed to be movable in an axial direction of the hub main bodyrelative to the adapter main body.

In another aspect of the present invention, a hub unit bearing which inan object of a method of manufacturing a hub unit bearing includes anouter ring, a hub, and a plurality of rolling elements. The outer ringhas an outer ring raceway having double rows on an inner circumferentialsurface thereof, and has a stationary flange protruding radiallyoutward. The hub has an inner ring raceway having double rows on anouter circumferential surface thereof. The plurality of rolling elementsare rotatably disposed between the inner ring raceway and the outer ringraceway. The stationary flange has a plurality of protruding portionsprotruding outward in a radial direction thereof. The hub includes a hubmain body and an inner ring, in which the inner ring is externallyfitted into a portion near one axial end portion of the hub main body,and the one axial end portion of the inner ring is pressed and held by acaulking portion formed by plastically deforming radially outward acylindrical portion provided at one axial end portion of the hub mainbody.

The method of manufacturing the hub unit bearing includes the processesof supporting the hub main body on the support portion so that thecentral axis of the hub main body is coaxial with the reference axis,engaging a tip portion of the block (at least one block in the case of aplurality of blocks) with the stationary flange such that power in arotating direction thereof can be transmitted by displacing the rotarydrive unit in the axial direction, driving the outer ring to rotate bydriving the rotary drive unit to rotate, and forming the caulkingportion by plastically deforming the cylindrical portion radiallyoutward by pressing the tip portion of the pressing die on thecylindrical portion while rotating the pressing die around the mainaxis.

In a method of manufacturing a vehicle according to another aspect ofthe present invention, a hub unit bearing is manufactured by the methodof manufacturing the hub unit bearing of the present invention asdescribed above.

Advantageous Effects of Invention

According to a rotary caulking device and a method of manufacturing ahub unit bearing of the present invention, it is unnecessary to performphase alignment of a rotary drive unit and a stationary flange in thecircumferential direction, and productivity can be improved and costscan be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a partial schematic view of a vehicle including a hub unitbearing (a bearing unit).

FIG. 2 is a cross-sectional view showing a hub unit bearing which is atarget of a first example of the embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a rotary caulking deviceaccording to the first example of the embodiment of the presentinvention.

FIG. 4 is an enlarged side view of a block taken out.

FIG. 5 is an end view showing a second example of a shape of a guidemember.

FIG. 6 is a cross-sectional view showing how the caulking portion isformed by using the rotary caulking device in the order of processes inthe first example of the embodiment of the present invention.

FIG. 7 is a schematic view showing a third example of an engagementstate between a tip portion of the block and a stationary flange.

FIG. 8 is a schematic view showing another example of the block.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a partial schematic view of a vehicle 100 including a hub unitbearing (a bearing unit) 1. The present invention can be applied to allof a hub unit bearing for a driving wheel and a hub unit bearing for adriven wheel. In FIG. 1, a hub unit bearing 1 is for a driving wheel,and includes an outer ring 2A, a hub 3A, and a plurality of rollingelements 4A. The outer ring 2A is fixed to a knuckle 101 of a suspensiondevice using bolts or the like. A wheel (and a braking rotor) 102 isfixed to a flange (a rotary flange) 9A provided in the hub 3A usingbolts or the like. Also, the vehicle 100 can have the same supportstructure as described above with respect to the hub unit bearing 1 fora driven wheel.

FIG. 2 shows a hub unit bearing (a bearing unit) 1 for a driven wheel.The hub unit bearing 1 includes an outer ring 2, a hub 3, and aplurality of rolling elements 4. The outer ring 2 has an outer ringraceway 5 having double rows on an inner circumferential surfacethereof, and a stationary flange 6 (a flange) protruding outward in aradial direction thereof at an intermediate portion in an axialdirection thereof. The stationary flange 6 has support holes 7 at pluralpositions in a circumferential direction thereof. The outer ring 2 iscoupled and fixed to a knuckle of a suspension device by bolts insertedor screwed into the support holes 7. This stationary flange 6 has anannular disc-shaped base portion 8, and protruding portions (ears) 9protruding radially outward from plural places (four places in theexample shown) in the circumferential direction on an outercircumferential surface of the base portion 8. Each of the support holes7 is provided in the protruding portion 9 to penetrate the protrudingportion 9 in the axial direction. The protruding portion 9 has a surface(an upper surface or a support surface) 6 a that intersects the axialdirection.

The hub 3 is disposed coaxially with the outer ring 2 on an innerdiameter side of the outer ring 2. Also, the hub 3 has an inner ringraceway 10 of double rows on an outer circumferential surface thereof.In addition, the hub 3 has a rotary flange 11 protruding radiallyoutward at an axially outer portion which protrudes axially outward overan axially outer end face of the outer ring 2. The rotary flange 11 hasmounting holes 12 at plural places in a circumferential directionthereof. The wheel and the braking rotor are supported by and fixed tothe rotary flange 11 by studs press-fitted into the mounting holes 12and nuts screwed onto tips portions of these studs.

Also, “outside” in the axial direction refers to the left side in FIG.2, which is outside of the vehicle in a width direction thereof in astate where the hub unit bearing 1 is assembled on the suspensiondevice. On the other hand, the right side of FIG. 2, which is inside ofthe vehicle in the width direction, is referred to as “inside” in theaxial direction.

The plurality of rolling elements 4 are disposed to be rollable betweenthe outer ring raceway 5 having double rows and the inner ring raceway10 having double rows with plural rolling elements 4 disposed in eachrow. Also, in the example shown, tapered rollers are used as the rollingelements 4. In another example, balls can also be used as the rollingelements 4.

In the example shown, the hub 3 has a hub main body (a unit main body)13 and a pair of inner rings 14 a and 14 b. The double rows of the innerring raceway 10 are provided respectively on an outer circumferentialsurface of each of the pair of inner rings 14 a and 14. The hub mainbody 13 has the rotary flange 11 on an outer side in the axialdirection. Also, the hub main body 13 has a cylindrical fitting surfaceportion 15 on an outer circumferential surface thereof in a range from amiddle portion to an inner side in the axial direction. In the hub 3,the pair of inner rings 14 a and 14 b are externally fitted into thefitting surface portion 15 of the hub main body 13. A caulking portion16 is provided at an axially inner end portion of the hub main body 13.An axially inner end face of the inner ring 14 a on an axially innerside thereof is pressed and held by the caulking portion 16. The hub 3is configured by coupling and fixing the pair of inner rings 14 a and 14b to the hub main body 13.

FIG. 3 shows a rotary caulking device 17. In the hub main body (unitmain body) 13 z (see (A) and (B) of FIG. 6) before the caulking portion16 is formed, one axial end portion (an axially inner end portion; anupper end portion in (A) and (B) of FIG. 6, has a cylindrical shape (acylindrical portion 31). The rotary caulking device 17 forms thecaulking portion 16 by plastically deforming (forging, heading,pressing, bending, etc.) the cylindrical portion 31 (the axial endportion of the cylindrical portion 31) outward in the radial direction.The rotary caulking device 17 includes a support portion (a base) 18 forloading the hub main body 13 z, a rotary drive unit 19 for driving theouter ring 2 to rotate, and a pressing die 20.

The support portion (base) 18 has a reference axis C in a verticaldirection. The hub main body 13 z is loaded on an upper surface of thesupport portion 18 such that the other axial end portion (an axiallyouter end portion; a lower end portion in (A) and (B) of FIG. 6) thereofis on a lower side, and its own central axis is coaxial with thereference axis C.

The rotary drive unit 19 includes a drive source (not shown) and anadapter (rotary drive jig) 80. The outer ring 2 moves around the axis ofthe hub main body 13 z via the adapter 80. The adapter 80 includes asupport plate (an adapter main body) 21 and a plurality of (eight in theexample shown) blocks 22. The support plate 21 is formed in a circulardisc shape centered on a central axis coaxial with the reference axis Cof the support portion 18. Also, the support plate 21 (adapter mainbody) is supported to be able to move up and down above the supportportion 18, that is, to be able to move closer to and away from thesupport portion 18. In addition, the support plate 21 is configured tobe rotatably supported about the central axis coaxial with the referenceaxis C and to be driven to rotate by means of the drive source (notshown) such as an electric motor. Further, the support plate 21 has seatportions 23 recessed upward at a plurality of places in thecircumferential direction on a lower surface thereof. Positioning andbuckling prevention of an elastic member (a biasing member) 27, whichwill be described later, are achieved by these seat portions 23.

In one example, each of the blocks 22 is at least partially made of aresin material. In another example, the block 22 is made of a materialother than resin. For example, as shown in FIG. 4, the block 22 includesa block main body 24 and a guide member 25 made of synthetic resin. Inthe present example, the block main body 24 is formed in a steppedcylindrical shape. The guide member 25 is externally fitted into andsupported by a tip portion (a lower end portion) of the block main body24. In this example, the guide member 25 is a rolling bearing or asliding bearing having a circular shape when viewed in the axialdirection, as shown in (A) of FIG. 5. In the case of the steppedcylindrical shape of the block main body 24, as in the present example,the block main body 24 can rotate. In another example, the guide member25 also may have a shape of, for example, a polygon (preferably aregular polygon) such as a regular hexagon, as shown in (B) of FIG. 5,when viewed in the axial direction. Also, the block 22 may also beformed in a prismatic shape of which cross-sectional shape is a regularpolygon such as a square or a regular hexagon. In this case, a rollingbearing or a sliding bearing whose outer circumferential surface is acylindrical surface can be externally fitted into and supported on thetip portion of the block.

In addition, when a rolling bearing is used as the guide member 25, anouter circumferential surface of the outer ring may be covered with asynthetic resin such as urethane, silicone, polyacetal, MC NYLON (aregistered trademark) which is a type of polyamide resin. By coveringthe outer circumferential surface of the outer ring with a syntheticresin, it is possible to prevent metal parts from colliding with eachother when a circumferential side surface of the protruding portion 9 ofthe stationary flange 6 is pressed by an outer circumferential surfaceof the guide member 25, so that damage to the stationary flange 6 can beprevented. Further, if necessary, a shaft-equipped rolling bearing inwhich a rotational shaft is supported by and fixed to the inner ring inadvance can also be used as the guide member 25. That is, the rotationalshaft of the shaft-equipped rolling bearing is supported at and fixed tothe tip portion of the block main body 24 by tight fitting or screwing,whereby the guide member 25 can be provided at the tip portion of theblock main body 24.

The plurality of blocks 22 are disposed movably in the axial directionof the hub main body 13 z relative to the support plate 21. The supportplate 21 has a plate member (an annular plate member) 21 a and a housingmember (a cover, a boss, a boss wall, or an annular wall) 26. The platemember 21 a and the housing member 26 are integrally formed.Alternatively, the housing member 26 is fixed to the plate member 21 a.The housing member 26 is disposed to surround the hub main body 13 z.The housing member 26 has a cavity (or a notch) 26 a in which the block22 is at least partially housed. Each of the plurality of blocks 22 isdisposed movably in the axial direction between a protruding state inwhich the block 22 protrudes at least partially in the axial directionfrom the support plate 21 (the adapter main body or the housing member26), and a housed state. In the housed state, an axial end face of theblock 22 abuts the upper surface 6 a (a first surface) of the stationaryflange 6 of the outer ring 2. In the protruding state, a side surface (acircumferential surface) of the block 22 is disposed to face the sidesurface (the side surface of the protruding portion 9 or a secondsurface) of the stationary flange 6 of the outer ring 2. The supportplate 21 (adapter 80) has a biasing member (elastic member) 27 thatapplies a force in a direction toward the hub main body 13 z to theblock 22.

For example, the block 22 may be supported below the support plate 21while a downward elastic force is applied thereto. That is, the block 22is fitted into a cylindrical cover 26 supported to surround an openingof the seat portion 23 on the lower surface of the support plate 21. Theelastic member (biasing member) 27 such as a torsion coil spring isdisposed between an upper end face of the block 22 and the bottomsurface of the seat portion 23. With this configuration, the guidemember 25 protrudes downward from a lower opening of the cover 26 in astate where no upward force is applied to a tip surface (a lowersurface) of the guide member 25 of the block 22. In addition, when theblock 22 is formed in a prismatic shape, the cover 26 can be formed in apolygonal tube shape. The block 22 can reliably protrude relative to thesupport plate 21 due to the elastic member 27. In another example,instead of the elastic member 27, an actuator for moving the block 22 inthe axial direction can be provided. Alternatively, the elastic member27 can be omitted by using gravity or a magnetic force.

The pressing die 20 is disposed to perform a caulking motion (a rotarycaulking motion or an orbital rotation motion) relative to the hub mainbody 13 z to which the inner ring 14 a is attached. The pressing die 20has a main axis α coaxial with the reference axis C, and a rotation axisβ inclined relative to the main axis α by a predetermined angle θ. Inaddition, a processing portion 28 for plastically deforming thecylindrical portion 31 of the hub main body 13 z radially outward toform the caulking portion 16 is provided at a tip portion (a lower endportion) of the pressing die 20. Specifically, the processing portion 28is configured by providing a convex portion 29 at the tip portion of thepressing die 20 and providing a curved surface portion 30 having anarc-shaped cross section on an outer circumferential surface of a baseend portion of the convex portion 29. This pressing die 20 is supportedto be able to move up and down above the rotary drive unit 19. Further,the pressing die 20 can be driven to rotate about the main axis α, andis rotatable about the rotation axis β.

A method of forming the caulking portion 16 by plastically deforming thecylindrical portion 31 of the hub main body 13 z radially outward usingthe rotary caulking device 17 will be described with reference to FIG. 6in addition to FIGS. 2 to 5. First, as shown in (A) of FIG. 6, the hubmain body 13 z before forming the caulking portion 16 is placed on thesupport portion 18 of the rotary caulking device 17 so that the otheraxial end portion is on the lower side, and the central axis of the hubmain body 13 z is coaxial with the reference axis C. Next, the pair ofinner rings 14 a and 14 b, the plurality of rolling elements 4 and theouter ring 2 are assembled around the fitting surface portion 15 of thehub main body 13 z.

Also, the order of assembling the pair of inner rings 14 a and 14 b, theplurality of rolling elements 4 and the outer ring 2 around the fittingsurface portion 15 is not particularly limited. Specifically, forexample, first, an axially outer side inner ring 14 b is externallyfitted into an axially outer half portion of the fitting surface portion15, and the rolling elements 4 are installed around the axially outerside inner ring 14 b. Next, the outer ring 2 is disposed around thefitting surface portion 15. Then, the rolling elements 4 are installedaround an axially inner side inner ring 14 a to form a subassembly, andthis subassembly is inserted between an axially inner half portion ofthe fitting surface portion 15 and an axially inner side outer ringraceway 5.

Alternatively, the pair of inner rings 14 a and 14 b, the plurality ofrolling elements 4 and the outer ring 2 may be made into a subassemblyin advance, and this subassembly may be installed around the fittingsurface portion 15.

After the pair of inner rings 14 a and 14 b, the plurality of rollingelements 4 and the outer ring 2 have been assembled around the fittingsurface portion 15, the adapter 80 of the rotary drive unit 19 is thendisplaced downward, as shown in (B) of FIG. 6. As a result, at least oneblock 22 of the plurality of blocks 22 and the protruding portion 9 ofthe stationary flange 6 are in a state in which they are capable ofengaging with each other (the protruding state) in a direction (adirection of rotating the outer ring 2 using the rotary drive unit 19)around the axis of the hub main body 13 z.

That is, the blocks 22 of the adapter 80 of the rotary drive unit 19 aredisposed at a plurality of places at equal intervals in thecircumferential direction centering on the central axis coaxial with thereference axis C of the support portion 18. Therefore, as shown in (A)to (C) of FIG. 7, among the blocks 22, some of the blocks 22 (the blocks22 represented by dashed-dotted lines in (A) to (C) of FIG. 7) havetheir tip surfaces at least partially facing axial end faces of theprotruding portions 9 of the stationary flange 6, and the remainingblocks 22 are disposed at positions circumferentially offset from theprotruding portions 9. An axial end face (a tip surface or a lowersurface) of at least one block 22 (and a portion of the lower surface ofthe support plate 21) abuts the upper surface 6 a (first surface) of thestationary flange 6 of the outer ring 2. As a result, the at least oneblock 22 is in the housed state housed in the support plate 21. Theremaining blocks 22 are in the protruding state in which the blocks 22at least partially protrude in the axial direction from the supportplate 21 (the adapter main body or the housing member 26). As a result,the side surface (circumferential surface) of the block 22 is disposedto face the side surface (the side surface of the protruding portion 9or the second surface) of the stationary flange 6 of the outer ring 2.

Further, downward elastic forces are applied to the blocks 22 by theelastic members 27. Therefore, when the adapter 80 of the rotary driveunit 19 is further displaced downward from a state in which the elasticmembers 27 are not elastically deformed, and a state in which verticalpositions of the tip surfaces (lower end surfaces) of the blocks 22facing axially inner surfaces of the protruding portions 9 coincide withan axially inner surface of the stationary flange 6, some of the blocks22 (whose tip surfaces face the axially inner surfaces of the protrudingportions 9) remain at the same vertical positions by elasticallydeforming the elastic member 27. On the other hand, the remaining blocks22 (whose tip surfaces face the positions circumferentially offset fromthe protruding portions 9) are displaced downward together with thesupport plate 21 so that the guide members 25 of the remaining blocks 22are disposed between the protruding portions 9 adjacent to each other inthe circumferential direction.

In this state, the adapter 80 of the rotary drive unit 19 is driven torotate clockwise in FIG. 7 about the central axis coaxial with thereference axis C. Then, the side surface of the protruding portion 9 ispressed at least in the circumferential direction by the outercircumferential surface of the guide member 25 of at least one block 22(the blocks 22 represented by thick lines in (A) to (C) of FIG. 7) ofthe blocks 22. At this time, for example, a portion of the block 22abuts on the support plate 21 to maintain the posture of the block 22.Thus, the outer ring 2 is driven to rotate, whereby the rolling elements4 rotate and revolve. As described later, when forming the caulkingportion 16, the formation of indentations on the outer ring raceway 5and the inner ring raceway 10 is prevented.

Next, the pressing die 20 is displaced downward while orbital rotatingthe rotation axis β of the pressing die 20 about the main axis α, like atrajectory of a central axis due to the precession motion. Theprocessing portion 28 of the pressing die 20 is pressed against thecylindrical portion 31 of the hub main body 13 z. For example, thenumber of rotations (rotational speed) of the rotating motion of therotation axis 3 of the pressing die 20 centered on the main axis α ismade different from the number of rotations (rotational speed) of therotary drive unit 19.

A downward load in the vertical direction and an outward load in theradial direction are applied to the cylindrical portion 31 from thepressing die 20. The portion to which the loads are applied in thismanner changes continuously in the circumferential direction of thecylindrical portion 31. As a result, the hub main body 13 z becomes thehub main body 13 in which the caulking portion 16 is formed byplastically deforming (caulking and expanding) the cylindrical portion31 outward in the radial direction. In addition, in the hub unit bearing1 after the caulking portion 16 is formed, the axially inner end face ofthe inner ring 14 a on the axially inner side is pressed and held by thecaulking portion 16, so that the pair of inner rings 14 a and 14 b areprevented from coming out of the fitting surface portion 15.

After the caulking portion 16 is formed, the rotation movement of thepressing die 20 is stopped, and the pressing die 20 is retracted upward.Subsequently, the rotary drive unit 19 is stopped to stop the rotationof the outer ring 2, and then the adapter 80 of the rotary drive unit 19is retracted upward. Then, the hub unit bearing 1 is obtained byremoving the hub main body 13 from the support portion 18.

According to the present embodiment as described above, it is notnecessary to align the adapter 80 of the rotary drive unit 19 and thestationary flange 6 in the circumferential direction, so that theproductivity can be improved and the costs can be reduced.

That is, the blocks 22 are disposed at a plurality of places at equalintervals in the circumferential direction on the rotary drive unit 19(adapter 80). The downward elastic force is applied to each block 22 bythe elastic member 27. For this reason, in the block 22 whose tipsurface faces the axially inner surface of the stationary flange 6 (theaxially inner surface of the protruding portion 9), the tip surface ofthe block 22 abuts the axially inner surface of the stationary flange 6as the rotary drive unit 19 is displaced downward. Even when the rotarydrive unit 19 (adapter 80) is displaced further downward, the elasticmember 27 is elastically deformed, whereby the block 22 remains at thesame vertical position. Therefore, regardless of the phase of the rotarydrive unit 19 and the stationary flange 6 in the circumferentialdirection, in a state in which the rotary drive unit 19 has beendisplaced downward, at least one of the blocks 22 and the protrudingportion 9 of the stationary flange 6 can be engaged such that power inthe rotating direction can be transmitted.

In addition, in the present embodiment, the guide member 25 which is arolling bearing or a sliding bearing using a synthetic resin isrotatably supported at the tip portion of the block 22. The side surfaceof the protruding portion 9 of the stationary flange 6 is pressed by theouter circumferential surface of the guide member 25 in thecircumferential direction. This prevents damage such as scratches frombeing generated on the circumferential side surface of the protrudingportion 9 and prevents the outer circumferential surface of the guidemember 25 from being worn.

Further, as in this example, in the structure in which the referenceaxis C of the support portion 18 is disposed in the vertical direction,the support portion 18 is disposed on a lower side, and the rotary driveunit 19 is disposed above the support portion 18, the elastic member 27disposed between the support plate 21 and the block 22 can be omitted byutilizing gravity.

In the case of practicing the present invention, the number of blocks ofthe rotary drive unit and the arrangement of the blocks in thecircumferential direction may be determined appropriately in accordancewith the shape of the stationary flange such that, when the rotary driveunit is displaced in the direction approaching the support portion, atleast one block of the plurality of blocks constituting the rotary driveunit and the stationary flange can be engaged to be able to transmitpower in the rotating direction regardless of the circumferential phaseof the rotary drive unit and the stationary flange. That is, as long asat least one block and the stationary flange can be engaged to transmitpower in the rotating direction, the plurality of blocks can be disposedat uneven intervals in the circumferential direction. Also, the numberof blocks can be set in accordance with the shape of the stationaryflange, and can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 or more. Forexample, the number of blocks may be 6 to 8.

The number of blocks may be six or less or one. When the rotary driveunit is displaced in the direction approaching the support portion, evenif the tip surfaces of all the blocks abut the protruding portions ofthe stationary flange (all the blocks are in the housed state), therotation of the adapter causes at least one block to shift to theprotruding state. That is, when the adapter of the rotary drive unit isrotated, the tip surface of at least one block slides on the axiallyinner surface of the protruding portion and faces the portion offsetfrom the protruding portion. Then, the block is axially displaced in thedirection approaching the support portion, so that the circumferentialside surface of the protruding portion can be pressed by the outercircumferential surface of the tip portion of the block.

FIG. 8 is a diagram showing another example of the block 22. As shown in(A) of FIG. 8, in the housed state, the entire guide member 25 of theblock 22 is disposed inside the housing member 26 in the support plate(adapter main body) 21. As shown in (B) of FIG. 8, in the protrudingstate, a portion of the guide member 25 of the block 22 protrudesrelative to the support plate 21 and the remaining portion of the guidemember 25 is disposed inside the housing member 26 in the support plate21.

The present invention can be applied not only to a hub unit bearing fora driven wheel whose hub main body is solid, but can also be applied toa hub unit bearing of a driving wheel in which a spline hole for torquetransmittable engagement of a drive shaft is provided at a center of ahub main body. Also, in the above, a case where the present invention isapplied to a so-called 2.5th generation hub unit bearing including a hubconfigured by externally fitting a pair of inner rings to a hub mainbody has been described. The present invention can also be applied to aso-called third generation hub unit bearing including a hub configuredby directly forming axially outer side inner ring raceways on an axiallyouter circumferential surface of a hub main body, and extremely fittingan inner ring on an axially inner side of the hub main body.

REFERENCE SIGNS LIST

-   -   1 Hub unit bearing    -   2 Outer ring    -   3 Hub    -   4 Rolling element    -   5 Outer ring raceway    -   6 Stationary flange    -   7 Support hole    -   8 Base portion    -   9 Protruding portion    -   10 Inner ring raceway    -   11 Rotary flange    -   12 Mounting hole    -   13, 13 z Hub main body    -   14 a, 14 b Inner ring    -   15 Fitting surface portion    -   16 Caulking portion    -   17 Rotary caulking device    -   18 Support portion    -   19 Rotary drive unit    -   20 Pressing die    -   21 Support plate (adapter main body)    -   22 Block    -   23 Seat portion    -   24 Block main body    -   25 Guide member    -   26 Cover (housing member)    -   27 Elastic member    -   28 Processing portion    -   29 Convex portion    -   30 Curved surface portion    -   31 Cylindrical portion    -   80 Adapter

The invention claimed is:
 1. A method of manufacturing a vehicleincluding a hub unit bearing, wherein the hub unit bearing ismanufactured using a rotary caulking device, the hub unit bearingincluding: an outer ring which includes an outer ring raceway havingdouble rows on an inner circumferential surface thereof and a stationaryflange protruding radially outward; a hub which includes an inner ringraceway having double rows on an outer circumferential surface thereof;and a plurality of rolling elements which are rotatably disposed betweenthe inner ring raceway and the outer ring raceway, wherein thestationary flange includes a plurality of protruding portions whichprotrude outward in a radial direction thereof, and the hub includes ahub main body and an inner ring, in which the inner ring is externallyfitted into a portion near one axial end portion of the hub main body,and the one axial end portion of the inner ring is pressed and held by acaulking portion formed by plastically deforming a cylindrical portionprovided at the one axial end portion of the hub main body radiallyoutward, the rotary caulking device including: a support portionincluding a reference axis; an annular support plate which is supportedto be able to move close to and away from the support portion and whichcan be driven to rotate about a central axis coaxial with the referenceaxis; a rotary drive unit including blocks which are supported at one ormore places of a circumference of the support plate to be able to bedisplaced in an axial direction thereof; and a pressing die which issupported to be able to perform a rotating motion about a main axiscoaxial with the reference axis, and is rotatably supported about arotation axis inclined relative to the main axis, the method ofmanufacturing the hub unit bearing comprising the processes of:supporting the hub main body on the support portion such that a centralaxis of the hub main body is coaxial with the reference axis; engaging atip portion of the blocks with the stationary flange such that power ina rotating direction thereof can be transmitted by displacing the rotarydrive unit in the axial direction; driving the outer ring to rotate bydriving the rotary drive unit to rotate; and forming the caulkingportion by plastically deforming the cylindrical portion radiallyoutward by pressing a tip portion of the pressing die on the cylindricalportion while rotating the pressing die around the main axis, wherein arolling bearing or a slide bearing is provided at a tip portion of theblocks.
 2. The method of manufacturing a vehicle according to claim 1,wherein the blocks are supported at a plurality of places of the supportplate in a circumferential direction thereof.
 3. The method ofmanufacturing a vehicle according to claim 1, wherein elastic forcesdirected in a direction toward the support portion with respect to theaxial direction are applied to the blocks.
 4. The method ofmanufacturing a vehicle according to claim 3, wherein elastic membersare installed between the support plate and the blocks.
 5. The method ofmanufacturing a vehicle according to claim 1, wherein the blocks arerotatably supported.
 6. The method of manufacturing a vehicle accordingto claim 1, wherein the rolling bearing is made of a synthetic resin. 7.The method of manufacturing a vehicle according to claim 1, wherein theslide bearing is made of a synthetic resin.
 8. A method of manufacturinga vehicle including a hub unit bearing, wherein the hub unit bearing ismanufactured by a method comprising: supporting a hub main body; andcaulking the hub main body to which an inner ring is attached; whereinthe caulking includes: pressing a pressing die on the hub main bodywhile the pressing die rotates; and moving an outer ring around an axisof the hub main body via an adapter, and the adapter includes: adaptermain body; and at least one block which is held in the adapter mainbody, and is disposed to be movable in an axial direction of the hubmain body relative to the adapter main body, wherein at least a portionof the block is made of a resin material.
 9. The method of manufacturinga vehicle according to claim 8, wherein each of the at least one blockis disposed to be movable in the axial direction between a protrudingstate in which the block at least partially protrudes in the axialdirection from the adapter main body, and a housed state, in the housedstate, an axial end face of the block abuts a first surface of the outerring, and in the protruding state, a side surface of the block isdisposed to face a second surface of the outer ring.
 10. The method ofmanufacturing a vehicle according to claim 8, wherein the adapterincludes a biasing member which is configured to apply a force in adirection toward the bearing unit to the block.